Johanna Lass-Hennemann

Cold pressor stress induces opposite effects on cardioceptive accuracy dependent on assessment paradigm.

Interoception depends on visceral afferent neurotraffic and central control processes. Physiological arousal and organ activation provide the biochemical and mechanical basis for visceral afferent neurotraffic. Perception of visceral symptoms occurs when attention is directed toward body sensations. Clinical studies suggest that stress contributes to the generation of visceral symptoms. However, during stress exposure attention is normally shifted away from bodily signals. Therefore, the net effects of stress on interoception remain unclear. We, therefore, investigated the impact of the cold pressor test or a control intervention (each n=21) on three established laboratory paradigms to assess cardioceptive accuracy (CA): for the Schandry-paradigm, participants were asked to count heartbeats, while during the Whitehead-tasks subjects were asked to rate whether a cardiac sensation appeared simultaneously with an auditory or visual stimulus. CA was increased by stress when attention was focused on visceral sensations (Schandry), while it decreased when attention was additionally directed toward external stimuli (visual Whitehead). Explanations for these results are offered in terms of internal versus external deployment of attention, as well as specific effects of the cold pressor on the cardiovascular system.

Endogenous cortisol levels influence exposure therapy in spider phobia

Previous research in patients with phobia showed that the administration of glucocorticoids reduces fear in phobic situations and enhances exposure therapy. Glucocorticoids underlie a daily cycle with a peak in the morning and low levels during the evening and night. The aim of the present study was to investigate whether exposure is more effective when conducted in the morning when endogenous cortisol levels are high. Sixty patients meeting DSM IV criteria for specific phobia (animal type) were randomly assigned to one-session exposure treatment either at 08.00 a.m. (high cortisol group) or at 06.00 p.m. (low cortisol group). Participants returned for a posttreatment assessment one week after therapy and a follow-up assessment three months after therapy. Both groups showed good outcome, but patients treated in the morning exhibited significantly less fear of spiders in the behavioral approach test (BAT) and a trend for lower scores on the Fear of Spiders Questionnaire (FSQ) than patients treated in the evening. This effect was present at posttreatment and follow-up. Our findings indicate that exposure therapy is more effective in the morning than in the evening. We suggest that this may be due to higher endogenous cortisol levels in the morning group that enhance extinction memory.

Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates

Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters mens preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates.

Presence of a dog reduces subjective but not physiological stress responses to an analog trauma

Dogs are known to have stress and anxiety reducing effects. Several studies have shown that dogs are able to calm people during cognitive and performance stressors. Recently, therapy dogs have been proposed as a treatment adjunct for post-traumatic stress disorder patients. In this study we aimed to investigate, whether dogs also have anxiety- and stress reducing effect during “traumatic stressors.” 80 healthy female participants were randomly assigned to one of four conditions. They were exposed to a “traumatic” film clip (trauma-film-paradigm). For one group of participants a friendly dog was present during the film, one group of participants was accompanied by a friendly human, another control group watched the film with a toy animal and the last group watched the film clip alone. Participants that were accompanied by the dog during the film reported lower anxiety ratings and less negative affect after the film clip as compared to the “toy dog group” and the “alone group.” Results of the “dog group” were comparable to the group that was accompanied by a friendly human. There were no differences in physiological stress responses between the four conditions. Our results show that dogs are able to lessen subjectively experienced stress and anxiety during a “traumatic” stress situation. This effect was comparable to that of social support by a friendly person. Implications for PTSD patients are discussed.

Lateralization effects on the cardiac modulation of acoustic startle eye blink

Cardiac modulation of startle eye blink has been introduced as a methodology to reflect baro-afferent signal transmission. Recent studies showed that affective startle modulation is specific to left-ear presentation that may be due to hemispheric specificity in processing emotional-relevant stimuli, similar to the processing of visceral- and baro-afferent stimuli. To explore whether cardiac modulation of startle eye blink is lateralized as well, 37 healthy volunteers received 160 unilateral acoustic startle probes of 105 dB(A) intensity presented to both ears, one at a time. They were elicited 0, 100, 230, and 530 ms after the R-wave of the cardiac cycle. Startle response magnitude was significantly diminished at a latency of 230 ms, which may be due to the baro-afferent neural feedback at this temporal location, but only for left-ear presentation. This lateralization effect in the cardiac modulation of startle eye blink may reflect the previously described advantages of right-hemispheric brain structures in relaying viscero- and baro-afferent signal transmission.

Accelerated trace eyeblink conditioning after cortisol IV-infusion

Impairing effects of cortisol on learning performance have been shown in human trace eyeblink conditioning. As the effect is observed from 30 min to hours after administration, a genomic action of cortisol is assumed. Here we report rapid cortisol effects that were observed during the first 10 min after cortisol administration in humans. Young healthy males (n=24) received the cortisol synthesis inhibitor metyrapone (1.5 g per os) to avoid interference of the endogenous pulsatile secretion of cortisol. Next, 2mg cortisol or placebo was infused intravenously, immediately before the trace conditioning task. The probability of the conditioned eyeblink responses was assessed electromyographically during the trace eyeblink conditioning task (unconditioned stimulus: corneal air puff, 10 psi, 50 ms; conditioned stimulus: binaural pure tone, 7 dB, 1000 Hz, 400 ms; empty interval between CS and US: 550 ms). Cortisol resulted in a faster increase of conditioning (p=.02), reaching a comparable level to placebo later on. This result extends the well-known effects of stress on the quality and amount of learning by showing that cortisol also affects the speed of learning. We propose that cortisol accelerates trace eyeblink conditioning via a fast, non-genomic mechanism. This fast action of cortisol is part of the adaptive strategy during the early stress response.

Effects of Acute Cortisol Administration on Perceptual Priming of Trauma-Related Material

Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD). They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a “traumatic” context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a “traumatic” context. Two groups of healthy volunteers (N = 160) watched either neutral or “traumatic” picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the “traumatic” stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a “traumatic” context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the “traumatic” stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a “traumatic” context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support the idea that administration of cortisol might be an effective treatment strategy in reducing intrusive reexperiencing.

Direct gaze of photographs of female nudes influences startle in men.

Foreground presentation of photographs of opposite sex nudes lowers startle elicited by sudden acoustic stimuli. However, the impact of gaze direction of the presented nudes on this startle modulation has not been investigated. Theoretically, direct gaze of photographs of female nudes could either lead to a larger inhibition of the startle reaction due to a summating valence and arousal effect of direct eye contact, or lead to a smaller inhibition due to an attention capturing effect of the eyes. Two subsets of erotic photographs of female nudes (women looking directly at the observer vs. gazing away) and standard IAPS neutral pictures were viewed by 26 male volunteers, while startle eye blink responses to binaural bursts of white noise (50 ms, 105 dB) were recorded by EMG. Erotic pictures reduced startle eyeblink magnitude as compared to neutral pictures. Furthermore, erotic stimuli without direct gaze at the observer showed a greater startle eyeblink inhibition than erotic stimuli with direct gaze at the observer. Our data suggest that direct gaze of opposite sex nudes may direct attention to the face, thereby reducing the appetitive impact of an attractive body.

From neuroscience to evidence based psychological treatments - The promise and the challenge, ECNP March 2016, Nice, France

This ECNP meeting was designed to build bridges between different constituencies of mental illness treatment researchers from a range of backgrounds with a specific focus on enhancing the development of novel, evidence based, psychological treatments. In particular we wished to explore the potential for basic neuroscience to support the development of more effective psychological treatments, just as this approach is starting to illuminate the actions of drugs. To fulfil this aim, a selection of clinical psychologists, psychiatrists and neuroscientists were invited to sit at the same table. The starting point of the meeting was the proposition that we know certain psychological treatments work, but we have only an approximate understanding of why they work. The first task in developing a coherent mental health science would therefore be to uncover the mechanisms (at all levels of analysis) of effective psychological treatments. Delineating these mechanisms, a task that will require input from both the clinic and the laboratory, will provide a key foundation for the rational optimisation of psychological treatments. As reviewed in this paper, the speakers at the meeting reviewed recent advances in the understanding of clinical and cognitive psychology, neuroscience, experimental psychopathology, and treatment delivery technology focussed primarily on anxiety disorders and depression. We started by asking three rhetorical questions: What has psychology done for treatment? What has technology done for psychology? What has neuroscience done for psychology? We then addressed how research in five broad research areas could inform the future development of better treatments: Attention, Conditioning, Compulsions and addiction, Emotional Memory, and Reward and emotional bias. Research in all these areas (and more) can be harnessed to neuroscience since psychological therapies are a learning process with a biological basis in the brain. Because current treatment approaches are not fully satisfactory, there is an imperative to understand why not. And when psychological therapies do work we need to understand why this is the case, and how we can improve them. We may be able to improve accessibility to treatment without understanding mechanisms. But for treatment innovation and improvement, mechanistic insights may actually help. Applying neuroscience in this way will become an additional mission for ECNP.

Analogue PTSD Symptoms are Best Predicted by State Rumination

Posttraumatic Stress Disorder (PTSD) is a severe mental disorder characterized by distressing intrusions. Since not all traumatized individuals develop PTSD, it is important to understand its underlying risk factors. So far, several psychological and physiological risk factors have been identified. However, these factors have rarely been examined together. An excellent tool to assess analogue PTSD in a prospective manner is the trauma film paradigm. This study examined relevant psychological and physiological factors in 60 healthy participants before, during and after the presentation of a “traumatic” film clip, including rumination, dissociation, anxiety, mood, cortisol and psychophysiology measures. Moreover, we assessed intrusions and administered the Impact of Event Scale – Revised (IES-R) for one week following the “trauma”. Surprisingly, the only significant predictor for both intrusion frequency and IES-R was rumination about the film (state rumination). Furthermore, intrusion distress was predicted by both state rumination and an increase in anxiety after the film clip. Our study highlights the relevance of rumination in PTSD. Further well designed clinical studies with PTSD patients should investigate these key variables prospectively to confirm our findings.